The disclosure relates generally to gas turbines and, more particularly, to a gas turbine operable in a dual fuel mode where a liquid fuel is injected into a multimixer tube.
Rotary machines, such as gas turbines, are often used to generate power for electric generators. Gas turbines, for example, have a gas path which typically includes, in serial-flow relationship, an air intake, a compressor, a combustor, a turbine, and a gas outlet. At least some known turbine engines have high specific work and power per unit mass flow requirements. To increase power output and operating efficiency, at least some known gas turbine engines use a liquid fuel (e.g., liquid hydrocarbons such as gasoline) rather than vapor fuel (e.g., natural gas).
The liquid fuel must be thoroughly mixed with combustion air in order to efficiently combust the liquid fuel. At least some known gas turbines mix natural gas with combustion air in a micromixer. The micromixer includes a tube with a plurality of perforations through which natural gas is introduced into the natural gas stream. The end of the perforations, or the injection points, are generally flush with the wall of the micromixer. The natural gas is able to mix with the combustion air because the natural gas is a vapor. However, liquid fuel introduced through the same perforations may not entrain with the combustion gas because the perforations do not introduce the liquid fuel far enough into the micromixer.